Metal springboard

ABSTRACT

A metal springboard particularly adapted for use in diving into swimming pools. The springboard is fabricated of aluminum or a similar metal, and is designed so that it can be continuously extruded. The cross-sectional shape of the preferred springboard is composed of a plurality of hollow sections, preferably inverted triangles with a strengthening member attached to the apex of each triangle. The use of this particular shape provides a board which is light in weight, resistant to torsional forces over the entire length of the board, and which has an extended service life due to the elimination of stress concentration and corrosion generating areas. The use of constant-area hollow tubes in conjunction with strengthening members permits the deflection curve of this board to be finely tailored for any chosen application.

United States Patent [191 Patterson 1 Jan. 28, 1975 1 METAL SPRINGBOARD [22] Filed: Oct. 13, 1971 [21] Appl. No.: 188,798

[52] US. Cl. 272/66 [51] Int. Cl. A63b 5/10 [58] Field of Search 272/66; 52/84, 588, 630, 52/730-732; 94/13 [56] References Cited UNITED STATES PATENTS 1,710,350 4/1929 DeWoitine 272/66 UX 2,396,625 3/1946 Watter 52/84 X 2,458,686 l/l949 Davie; 52/630 X 2,747,871 5/1956 Brandt et a1. 272/66 2,805,859 9/1957 Rude 272/66 2,807,468 9/1957 Pattersonw. 272/66 2,831,688 4/1958 272/66 2,864,616 12/1958 Rude 272/66 2,952,341 9/1960 Weiler 52/630 X 2,963,294 12/1960 Buck.... 272/66 3,072,401 l/l963 Rude 272/66, 3,100,556 8/1963 DeRidder.... 52/630X 3,322,448 5/1967 Rolland 52/731 X 3,408,069 10/1968 Lewis 272/66 3,416,793 12/1968 Fox 272/66 FOREIGN PATENTS OR APPLICATIONS 945,293 12/1963 Great Britain 272/66 Primary Examiner-Richard J. Aplcy Attorney, Agem, 0r Firm-Wood, Herron & Evans [57] ABSTRACT A metal springboard particularly adapted for use in diving into swimming pools. The springboard is fabricated of aluminum or a similar metal, and is designed so that it can be continuously extruded. The crosssectional shape of the preferred springboard is composed of a plurality of hollow sections, preferably inverted triangles with a strengthening member attached to theapex of each triangle. The use of this particular shape provides a board which is light in weight, resistant to torsional forces over the entire length of the board, and which has an extended service life due to the elimination of stress concentration and corrosion generating areas. The use of constant-area hollow tubes in conjunction with strengthening members permits the deflection curve of this board to be finely tailored for any chosen application.

2 Claims, 8 Drawing Figures METAL SPRINGBOAR BACKGROUND OF THE INVENTION Diving boards which are formed from a plurality of elongated members connected together in a side-byside relationship are old in the art. Previously developed composite diving boards have been assembled by riveting, bolting, welding, or other methods. These composite boards have inherent drawbacks in the method of assembly; the major drawback being that no satisfactory method has been devised for fastening or attaching these multiple sections together in an absolutely rigid fashion. The fact that limited motion between members is always present reduces the service life of the board because of wear, corrosion, and the effects of stress concentrations.

Diving boards have also been fabricated using a plurality of vertical ribs under the surface of the board. This type of board has generally been constructed from a thin horizontal plate with dependent ribs on the un-- SUMMARY OF THE INVENTION The principal objective of the present invention is to provide a completely new and different unitary diving board which is preferably formed from a single extruded metal section. The cross-section of the springboard is a combination of geometrical shapes which produce remarkably superior torsional resistance qualities and longitudinal deflection qualities which can be tailored to the exact requirements of a particular application. The present invention utilizes a combination of hollow sections which preferably are triangularly or truss-shaped longitudinal tubes joined in side-by-side relationship along with longitudinal strengthening members, one of which is generally disposed under each triangularly shaped tube. As indicated above, it is preferable to form the diving board in a single extrusion in order to eliminate the need for joining sections together along their lengths. However, economics and extrusion technology may not permit a completely integral diving board. It is to be understood, however, that it is preferred that as many hollow sections as possible be extruded integrally within the limits of extruding technology.

The hollow triangular tubes provide a structure which is both light in weight and highly resistant to torsional forces. Previous diving boards constructed of open geometrical sections have been expensive to fabricate. One patent discloses a typical example of the prior art construction wherein the fabricating operation of forming a square tube into one tapered at one end by inwardly collapsing both side walls simultaneously, is a complicated and expensive process. Additionally, the multiple tubes must be bolted or attached together internally. External strips to fill in the concave side walls are also required. As compared to this structure, the'present invention can be seen to eliminate stress concentrations, corrosion due to a relative motion between the tubes at points of intimate contact, corrosion due to dissimilar metals present at bolt locations and attachment points, and greatly decreased assembly costs.

The present invention provides a construction of hollow geometric shape requiring inexpensive fabrication operations, having minimal stress concentration areas, and providing improved control over the longitudinal spring characteristics of the board.

The use of hollow tubes, as set forth in this invention, permits a diving board to be constructed with a great saving in weight over a flat plate-type board with the same torsional characteristics. Another patent discloses a unitary metal springboard typical of the prior art. The present invention provides remarkably improved torsional characteristics over this type of construct'ion. Since the triangular tubes are of constant cross-section, the torsion characteristics are substantially constant over the boards length as opposed to the flat plate with ribs where the torsional characteristics vary withlength because the ribs are tapered.

Prior art attempts in improving the torsional characteristics of this type of construction are shown in another patent. This patent discloses a separate torsion brace which is adapted to be attached to the underside of the diving board. All the inherent advantages of a unitary construction are thereby lost when a separate structure is attached to a previously unitary board. The

board is then subject to stress'concentrations, dissimilar metal corrosion, and reduced service life as a consequence of the assembling operation. The present invention eliminates these problems because the board is extruded with superior'torsional characteristics designed in rather than having the characteristics bolted on or attached at a later time.

Perhaps the prime design objective of the diving board industry is to provide a board with a proper deflection curve for a particular application. It is important that the free end of thediving board *stay" with the feet of the diver as the board thrusts the diver upwardly. The deflection curve of the board for any particular application is generally readily calculable. The longitudinal spring characteristics required to generate a chosen deflection curve can then be determined. The present invention can be constructed with any flexing characteristics desired by varying the size of the triangular tubes, the wall thickness of the triangular tubes, the apex angle of the triangular tubes, or the material extruded.

For certain installations, further control over the longitudinal deflection curve can be obtained with longitudinally extending strengthening members which may be attached to the apices of the triangular tubes. In a pre-v ferred embodiment, these members generally comprise the stem of a T-section and are extruded with the triangular tubes. The crossbar of the T-section may serve as a support in the fulcrum area and also as a support at the rear of the board where the board is restrained. Both the crossbar of the T-section and the stem of the T-section may be removed in any fashion calculated to provide the desired deflection curve. In this manner, the longitudinal deflection curve of the springboard may be generated without affecting the torsional characteristics of the board.

I DESCRIPTIONOF THE DRAWINGS FIG. 1 is a side elevation of a diving board embodying the principles of the present invention;

FIG. 2 is an enlarged sectional view taken substantially in the plane of line 2-2 of FIG. 1',

FIG. 3 is an enlarged sectional view taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is an enlarged sectional view taken substantially along the line 4-4 of FIG. 1;

FIG. 5 is a fragmentary sectional view taken substantially along the plane of the line 5-5 of FIG. 4;

FIG. 6 is a fractional section view taken along the plane of the line 66 of FIG. 4;

FIG. 7 is a sectional view of an alternate embodiment of the longitudinal board members with centrally locatedL-shaped joining members; and

FIG. 8 is a fragmentary sectional view of one alternate embodiment. of the longitudinal strengthening members.

Referring now to the accompanying drawings in detail, the general reference numeral 10 designates a diving springboard supported in a conventional manner by a fulcrum 11 at a fulcrum point 27 and a rear restraining means 12 at the fixed end of the board. The rear restraining means 12, generally includes an upper plate 14 with bolts extending through the springboard 10 to the horizontal member of the restraining means. Both the restraining means 12 and fulcrum means 11 are generally fixedly embedded in a concrete pool apron 13.

The preferred embodiment of the springboard 10 is of a metallic construction, is comprised of a plurality of longitudinal members, of generally triangular crosssectiomextruded integrally in an edge-to-edge contacting relation. As used herein, the term extruded integrally is intended to define that structural quality of the element which is monolithic and formed of one piece by an extrusion process as contrasted to a member which is built up of a plurality of separate shapes and joined together as by welding or riveting. As is best shown in FIG. 2, the bases of the triangularly shaped members form a substantially horizontal upper plate 16. The upper plate 16 is of generally constant vertical thickness denoted by numeral 25 except at the common points ofthe longitudinal members denoted by numeral 17, where the vertical thickness of metal is approximately three times that of the average wall thickness 25. In the preferred embodiment, the wall thickness 25 of the lower two sides of the triangularly shaped members is equal with that of the base 25. From the cross-sectional view of FIG. 2 it is apparent that the springboard of this invention can be continuously extruded such that the triangularly shaped longitudinal members are formed along with the vertical strengtheningmembers which are joined at the apex angle 18.

The vertical strengthening members in this embodimentconsist of an inverted T-shaped member, the stem 19 of which is joined to the apex angle 18 and the crossbar of which is disposed below the stem 19 and extends in the general horizontal plane. The crossbar 20 serves to support the board 10 on the horizontal member'27 of the fulcrum 11. The extrusion die can be formed to provide typical radii 26 in the springboard 10. These radii 26 provide a board which is both free of stress concentrations and also attractive in appearance.

By referring to FIGS. 2, 3 and 4, corresponding to stations 2-2, 3-3 and 4--4'of FIG. 1, it is apparent that the triangularly shaped longitudinal tubes do not change in cross-section over the length of the board. In contrast, however, the vertical strengthening member 19 can be tapered towards the free end of the board as shown in FIGS. 2, 3 and 4. The tapering of this member 19 is accomplished by grinding or removing the lower part of theextruded strengthening member. Since an extruded board contains a complete vertical strengthening member extending along its entire length when first extruded, each individualboard can be tailored for a specific application by selectively removing only sufficient material from the vertical strengthening member to provide the deflection characteristics desired. By way of illustration, a diving board intended primarily for use by children would have more material removed from the strengthening member than would a diving board intended for a primary use by adults.

The cross-sectional configuration of FIG. 4 extends over a substantial portion of the board and creates .a very attractive appearance at the more visible flexing end of the board.

In FIG. 1, the taper of member 19 is shown to be substantially continuous from the fulcrum of point 27 to the tip 15 of the board. This embodiment is only shown as being typical of present practice of mass-produced diving boards. The present invention is not limited to this continuous taper, as itcan be envisioned that certain applications will require the vertical rib to assume a shape other than a continuous taper. Additionally, the vertical ribs admit of a double taper, that is tapering in both directions away from the fulcrum. The longitudinal tubes are of essentially constant cross-sectional area 23 and are designed such that the wall thickness 25 in combination with the shape determined by the apex angle 18 and base angle 31, provided substantially all the spring characteristics in the longitudinal plane and the torsional resistance in the transverse plane. The vertical strengthening members, in this embodiment denoted by Hand 20, are primarily used to tailor the longitudinal spring characteristics provided by the longitudinal tube rather than govern the longitudinal spring characteristics.

Referring to FIG. 5, the rubber tip 15 is shown extending beyond the end of the diving board. The tip 15 has a cross-section identical with that of the longitudinal tube shown in FIG. 4. In addition, this tip is provided with a centrally disposed core or plug insertable within the hollow portion 23 of the longitudinal tubes. The tip 15 is securedly mounted to the end of the diving board either by internal friction against the walls 25 or by other suitablemeans.

Referring to FIG. 6, it can be seen that the rubber tip 15 at point 17 of FIG. 2, does not have a central core or plug, but merely extends transversely between longitudinal tubes in an abutting relationship to the wall 17.

FIG. 7 discloses an alternate embodiment where it would be desirable to extrude the board using smaller extrusion dies. In this embodiment, the board can be extruded in the cross-section shown which includes an L-shaped member consisting of a leg portion 21 and a foot portion 22. The foot portions of these L-shaped members can be joined along the longitudinal centerline 24 of the board by riveting, welding or the like, It can be seen that one extrusion die provides both longitudinal halves of the board and, after these halves have been joined as in FIG. 7, the vertical strengthening members can be tapered or removed in the fashion shown in FIGS. 2, 3 and 4.

FIG. 8 discloses an alternate embodiment of the vertical strengthening member. The vertical strengthening member of this cross-section is equally as desirable as an inverted T-shaped or any other strengthening member of substantial vertical dimension. As shown in FIG. 8, this strengthening member consists of an essentially inverted V-shaped member having two legs extending downwardly at an acute angle .to the vertical. Each leg 28 may be provided with a foot 29 located at the lower end of each leg. The feet 29 may be capped by a rubber' extrusion 30 and generally rest on the fulcrum support point 27 and provide a bearing surface of increased area. The wall thickness 32 of legs 28 may be the same as the wall thickness 25 of the longitudinal tubes or may vary depending on the design requirements of the board.

The embodiment of FIG. 8 has the advantage over the T-shaped embodiment in that in machining the taper into the board the creation of sharp, feather edges, such as occurs at the end of the horizontal bar 20, is substantially eliminated.

While in the foregoing there have been described and shown the preferred embodiments of the invention, various modifications may become apparent to those skilled in the art to which the invention is related. Accordingly, the invention is not limited to this disclosure and various modifications and equivalents may be resorted to, falling within the spirit and scope of the invention as claimed.

What is claimed as new is:

l. A metal springboard comprising,

a plurality of elongated longitudinal members extruded integrally with each other, said longitudinal members being triangularly shaped hollow tubes of constant wall thickness.

said members extending transversely to the longitudinal axis such that the apex of each triangularly shaped member is disposed downward to form the underside of the springboard and the base opposite the apex is disposed in a horizontal plane,

said bases being mutually co-planar and forming the upper surface of the board,

said members integrally joined to each adjacent member at a cross-sectional angle other than the apex angle to form an elongated, thin, narrow board.

2. A metal springboard comprising,

1 a plurality of elongated longitudinal members extruded integrally with each other and of generally triangular cross-section,

. said members extending transversely to the longitudi nal axis such that the apex of each triangularly shaped member is disposed downward to form the underside of the springboard'and the base opposite the apex is disposed in a horizontal. plane,

.said bases being mutually co-planar and forming the upper surface of the board,

said members integrally joined to each adjacent member at a cross-sectional angle other than the apex angle to form an elongated, thin, narrow board,

the vertical thickness of the metal at the common points between adjoining members being approximately three times the thickness of the bases of said triangular members. 

1. A metal springboard comprising, a plurality of elongated longitudinal members extruded integrally with each other, said longitudinal members being triangularly shaped hollow tubes of constant wall thickness, said members extending transversely to the longitudinal axis such that the apex of each triangularly shaped member is disposed downward to form the underside of the springboard and the base opposite the apex is disposed in a horizontal plane, said bases being mutually co-planar and forming the upper surface of the board, said members integrally joined to each adjacent member at a cross-sectional angle other than the apex angle to form an elongated, thin, narrow board.
 2. A metal springboard comprising, a plurality of elongated longitudinal members extruded integrally with each other and of generally triangular cross-section, said members extending transversely to the longitudinal axis such that the apex of each triangularly shaped member is disposed downward to form the underside of the springboard and the base opposite the apex is disposed in a horizontal plane, said bases being mutually co-planar and forming the upper surface of the board, said members integrally joined to each adjacent member at a cross-sectional angle other than the apex angle to form an elongated, thin, narrow board, the vertical thickness of the metal at the common points between adjoining members being approximately three times the thickness of the bases of said triangular members. 